Use openjson to get columns from JSON with multiple arrays of elements

Question

JSON input looks like this:

{
"reporting.unit": [ "F-1", "F-2", "F-3"],
"notional.lc": [  100.1, 140.2, 150.3]
}

Desired Output:

reporting.unit	notional.lc
F-1	100.1
F-2	140.2
F-3	150.3

Note I have upwards of 20 columns and many more elements

I tried:

    DECLARE @json nvarchar(max);
    SELECT @json = '{
    "reporting.unit": [ "F-1", "F-2", "F-3"],
    "notional.lc": [  100.1, 140.2, 150.3]
    }';
    SELECT *
    FROM OPENJSON (@json);

but the result was:

key	value	type
reporting.unit	[ "F-1", "F-2", "F-3"]	4
notional.lc	[ 100.1, 140.2, 150.3]	4

Answer 1

You can use OPENJSON with multiple JOIN's to join your columns together using your array keys to get the values in a column/row format.

DECLARE @json nvarchar(max);
SELECT @json = '{
"reporting.unit": [ "F-1", "F-2", "F-3"],
"notional.lc": [  100.1, 140.2, 150.3]
}';
SELECT 
  a.value AS [reporting.unit],
  b.value AS [notional.lc]
FROM OPENJSON(@json, '$."reporting.unit"') a
JOIN OPENJSON(@json, '$."notional.lc"') b 
ON a.[key] = b.[key]

Result:

reporting.unit	notional.lc
F-1	100.1
F-2	140.2
F-3	150.3

Demo here.